#include <iostream>
using namespace std;
class Complex {
public:
    Complex(){};
    Complex(double real, double imag);
    Complex comp_add(Complex&);
    void display();
    Complex operator+(Complex&);
    friend ostream& operator<<(ostream&, Complex&);
    friend istream& operator>>(istream&, Complex&);
private:
    double real;
    double imag;
};
class Complex1 {
public:
    Complex1(){};
    Complex1(double real, double imag);
    void display();
    friend Complex1 operator+(Complex1&, Complex1&);
private:
    double real;
    double imag;
};

class String {
public:
    String();
    String(char* str);
    void display();
    friend bool operator>(String&, String&);
    friend bool operator<(String&, String&);
    friend bool operator==(String&, String&);
    friend void compare(String&, String&);
private:
    char* p;
};

class Time {
public:
    Time();
    Time(int, int);
    Time operator++();  // 前置++运算符
    Time operator++(int);  // 后置++运算符
    void display();
private:
    int minute;
    int second;
};